Electric vulcanizer



o. C. D`ENN|S. ELECTRIC VULCANIZER.

APPLlCATlON FILED NOV. 26, 1915.

Patented July 15, 1919.

OLIVER C. DENNIS, OF CHICAGO, ILLINCIS.

ELECTRIC VULCANIZER.

Specification of Letters Patent.

Patented July 15, 1919.

Application led November 26, 1915. Serial No. 63,405.

To all whom t may concern:

Be it known that I, OLIVER C. DENNIS, a resident of Chicago, in thecounty of Cook and State of Illinois, have invented certain new anduseful Improvements in Electric Vulcanizers, of which the following is afull, C

clear, and exact description.

The invention relates to electric vulcanizers of the type set forth inLetters Patent No. 1,147,847, granted to me July 2.7, 1915, and itsobject is to improve and simplify the construction therein set forth.

In the device set forth in said patent. the electric circuit includes acontact between a manually shiftable switch-member and a ratchet wheelwhich is controlled by the fusible resoldering connection. If animperfect contact was made between the springcontact and the ratchet,the free flow of current through the resistance element would beprevented, and direct heating of the ratchet and melting of the solderwould result before the resistance element reached the desiredltemperature for vulcanizing. To overcome this inaccuracy, thepresentin* vention designs to provide an improved electric vulcanizer inwhich there is a cut-out for the circuit when the vulcanizingtemperature is reached, controlled by a fusible connection, and in whichthe circuit for the resistance element is maintained without dependingupon the engagement of the contact and ratchet.

A further object of the invention is to provide a structure in which thecase is not utilized as an electrical conductor and in which provisionis made for preventing the current from being short-circuited betweenthe exposed binding-posts, such as would occur if the vulcanlzer wereplaced where both of the binding-posts for the flexible conductors wouldrest against or touch a conductin wall or support.

Other o jects of the invention'will be aparent from the detaileddescription of the invention.

The invention consists in the several novel features hereinafter setforth and more particularly defined by claims at the conclusion hereof.

In the drawings: Figure 1 is an inverted.

plan of a vulcanizer embodying the invention, the bottom plate beingremoved. Fig. 2 is a section on line 2-2 of Fig. 1. Fig.

3 is a section taken on line 3-3 of Fig. l. Fig. 4 is a section taken online 4-4 of Fig. 1. Fig. 5 is a detailof one of the split sleevecontacts forming a part of the detachable terminal lfor one oftheflexible conductors.

The improved vulcanizing device coin-I slots therein to receiveclamping-screws or devices whereby a suitable plate may be secured tohold a tire-tube or work to be vulcanized in contact'- with thebottom-plate 12 o f the case or for-connection of suitable devices forholding the curved top-portion 14 of the vulcanizer -in contact witha'tire-casing, as well understood in the art. "A chamber 15 is formedinthe body of the casing and this chamber contains a resistance element16, a controlling switch and the automatically resoldering connectionwhich controls the opening of the switch when the work has beenvulcanized.

Plate 12 is secured by screws 17 to close the bottom of the chamber 15and to form the bottom of the casing. The resistance-element 16 is inthe form of a coil of flat wire wrapped around a core consisting of astrip of asbestos 19 held between a pair of strips 18 of insulatingmaterial, such as mica. Strips of similar' insulating material 20 arelaid between the resistance wire and the top of the casing and a stripof similar insulating material 21 and asbestos 22 are interposed betweenthe resistance element and the bottom-plate 12. These insulatingmaterials 'prevent current from passing from the resistance element tothe case and the asbestos serves to distribute the heat over sufficientlarea to roperly heat the work. One end of the resistance element 16 isconnected to a binding-post 24, which is in the form of a screw 25 andis clamped to the casing by a nut 26 and insulated therefrom by washers27. The other end. of the resistance element is extended between a pairof plates 28, 29 between which it is clamped by screws 30 which securethe plates in the case and are insulated from the plates by washers 31and insulating plates 32 and 33. The outer ends of plates 28 and 29 aredivergent, as at 34, to receive and frictionally and rmly engage anlinturned lug 35 on a resilient switch-member 36. One end of 29 and closethe circuit at this switch.

switch-member 36 is secured to a bindingpost 37, similar in constructionto the binding-post 24 and insulated also in similar manner from thecase.

The binding-posts are adapted for connection to fiexible conductor-wires38 and 39 which are connected to a battery or source of potential, andeach of these wires is provided with a terminal comprising a socket 40of insulating material and a split contactsleeve 41 secured in thesocket by a screw 42. The head 43 of screw 42 is countersunk and coveredwith insulating material 44. The split-sleeve 41 is adapted tofrictionally engage and to be pushed into firm contact with the taperedend of the screw 25 of the binding-post. Socket 40 is adapted to passover the lock-nut 26 of the binding-post, so that when the vulcanizer isconnected to a battery, the exposed portions of the binding posts willbe covered and protected against contact with any conducting material,whereby a short circuit might be established between the two bindingposts and the vnlcanizer. This feature of effectively guarding againstany short-circuiting is important, because in a vulcanizer with anautomatic cut-out, it is customary to leave the vulcanizer unattendedduring the vulcanizing operation, the cut-out being depended upon toopen the circuit when the vulcanizing operation has been completed.Obviously, anyv short circuit between the two binding posts wouldprevent the current from flowing to the resistance element when theswitch is closed.

The automatic fusible resoldering connection comprises a ratchet wheel45 held on a stud 46 which is screwed into a plate 47, which is securedin the case by screws 30, which clamp it between the contact-plate 28and insulating material 32. Plate 47 is insulated from said screws bysleeves 31a. A sleeve 48 is interposed between the ratchet 45 and plate47 and the ratchet is held on stud 46 by the head 462i of said stud. Afilm of solder 49 is interposed between ratchet 45 and head 46a and thissolder is fusible atvulcanizing temperature. A retaining member 50 issecured to the movable end of switch-member 36 and is provided with aslot 51 to receive the teeth of ratchet 45 and a push-button 52 ofinsulating material is secured to the same end of spring-contact 36 andextends through a hole in one side of the case, so that it can bemanipulated from the outside thereof.

lVlien the button 52 is pressed inwardly, the retaining member 50 willengage the ratchet wheel and will be held thereby. At the same time, lug35 on switch-member 36 will pass between the contact-membersC 28,

rent will then fiow over a circuit as follows:

conductor 38, screw 42 and split-sleeve 41, to which the terminal ofsaid conductor is connected, screw 25 of'binding-post 24, resistanceelement 16, contact plates 28, 29, contact-lug 35, switch-member 36,binding-post 37 and conductor 39. This circuit will remain closed untilthe resistance element has produced sufficient heat to bring the case tothe highest temperature desired in vulcanizing, usually from 250 to 285OFahr. At that time, the solder 49 will fuse so that the inherentresiliency of switch-member 36 will pull the retaining member 50outwardly and cause it to slip off of the tooth of the ratchet wherebyit has been held. Thus, the vulcanizer will automatically open thecircuit when the polymerization point has been reached, so that the workwill not be over heated and will be properly vulcanized.

It will be observed that the circuit is.

closed at lug 35 on the switch-member 36 and the contact-plates 28 and29, which are securely clamped to one terminal of the resistanceelement, so that a circuit will be established which does not dependupon any point contact between the retaining member 50 and the ratchet45 and that the lug 35 and contact-plates 28 and 29 operate as aknife-switch for obtaining effective connection for the flow of currentto the resistance element.

It will also be observed that the circuit is insulated from the case andthat provision was made for connecting the detachable conductorterminals from the battery to the binding-posts, which avoid thepossibility of any short circuiting between the bindingposts.

The device is simple in construction and can be produced at a low cost.

The invention is not to be understood as restricted to the details setforth, since these may be modified within the scope of the appendedclaims, without vdeparting from the spirit and scope of the invention.

Having thus described the invention, what I claim as new and desire tosecure by Letters Patent, is:

1. In a. portable electric vulcanizer, the combination of a case, anelectrical resistance element in the case, a switch for controlling thefiow of current through said element comprising a resilient memberwithin the case and having one of its ends fixed to and insulated fromthe case and another member fixed to and insulated from the case andconnected to said element, a button fixed to the movable end of theresilient member and extended to the outside of the case, and anautomatic cut-out for releasing the resilient member when thevulcanizing temperature is reached.

2. In a portable electric vulcanizer, the combination of a case, anelectric resistance 'element in tlie case, :L switch for controlling abutton extended to the outside of the case the flow of current throughsaid element for operating the resilient member, and un comprising uresilient member Within the' 4automatic cut-out for releasing theresilient 10 case and having one of its ends fixed to and member whenthe vulcanizing temperature insulated from the case and another memberis reached.

consisting of a pair of plates between which one end of the resistanceelement is clamped, OLIVER C. DENNIS.

